# Part III — Scenario Runtime

These chapters describe what happens while a scenario runs: traffic, verification, capabilities, and observation.

The same runtime serves all three declarative entry patterns: uniform clusters, composed app stacks, and attached external nodes.

- [Workloads and Concurrency](workloads.md) — driving the system under test
- [Expectations and Evaluation](expectations.md) — verifying outcomes
- [The Verb Layer](verb-layer.md) — concise domain actions over the explicit builder API
- [Scenario Capabilities](capabilities.md) — capability-gated features such as node control
- [Chaos and Controlled Failure](chaos.md) — restarts and failover from workloads
- [Runtime Extensions](runtime-extensions.md) — typed scenario-lifetime services
- [Continuous Observation](observation.md) — snapshots, history, and event streams for test logic
- [Telemetry and External Observability](telemetry.md) — metrics, logs, and tracing